This invention relates to locking devices, some of which are sometimes referred to as seals, and more particularly, to devices in which an elongated member is locked to a tapered housing bore upon axial displacement of the member relative to the housing.
Of interest are commonly owned copending applications entitled "Reusable Seal for Use with Rod" Ser. No. 106,428 filed Aug. 13, 1993 in the name of George Georgopoulos et al. and Ser. No. 221,589 entitled "Seal" filed Apr. 6, 1994 in the name of George Georgopoulos et al. See also commonly owned U.S. Pat. No. 5,347,689.
Locking devices generally are known and widely used. For example, U.S. Pat. No. 5,222,776 discloses one such device wherein a flexible metal cable has one end permanently secured in a housing bore via an enlarged member secured to that one end. The cable other end is secured selectively in a second housing bore which is tapered by a pair of balls and a spring. The balls wedge against the cable for locking that end in the tapered bore when the cable is displaced in a direction to withdraw the cable from the bore. This is relatively complex and uses a number of different elements which add to the cost of the device.
Another locking arrangement is disclosed in U.S. Pat. No. 4,802,700. In this patent an annular channel is formed in a rod and in a lock body bore. A ring in the channels locks the rod to the lock body. this device, however, is not disclosed as usable with a stranded cable.
U.S. Pat. No. 4,097,164 discloses an arrangement for securing a strand to a terminal body using a deformable member surrounding the strand. The body is deformed to deform the member to secure the strand to the terminal body. This arrangement is not reusable as the body is deformed to secure the strand thereto.
U.S. Pat. No. 4,802,699 discloses securing a bolt to hasps with a locking portion comprising a plurality of parallel spaced grooves in the bolt and a cylindrical member having snap rings which engage the bolt grooves. The member provides a camming action to lock the member on the snap rings.
U.S. Pat. No. 1,808,075 discloses two complementary members for gripping a rope therebetween. A plurality of fingers are formed in the member to grip the rope. the members are held together by a ring. The members are provided with tongues to preclude relative displacement. The members are mounted in a tapered passage of an eye member which secure the members to the rope and to the eye member.
U.S. Pat. No. 968,665 discloses a U-shaped sheet material clip having bent over facing flat sheet material bent arms with a V-shaped notch on one arm end and an opening at the juncture of the arms. One end of a flexible rope element is knotted to secure it in a casing in which the clip is located. The free end is passed between the bent arms of the clip and through the notch and opening. The notch precludes withdrawal of the rope element therethrough.
Other locking arrangements employ cable or rod gripping collets including fingers or segments which engage a casing tapered bore and which also engage a received cable in the bore. The fingers wedge the cable when it is withdrawn from the smaller end of the tapered bore. See for example U.S. Pat. Nos. 3,524,228; 4,333,649 and 2,144,050.
All of the above structures are adapted for different locking conditions, are relatively costly and usually are designed for a given cable or rod outer dimensions. The present inventors recognize a need for a locking device which is simple, uses few components and which is adaptable for gripping cables or rigid rods.
Further, a need is seen for a locking device which is capable of locking to cables of different diameters. Typical quarter inch (6 mm) diameter cables may vary as much as 0.020 inches (0.5 mm) in diameter. This is a problem with the finger collet arrangements which are generally designed to mate only with cables of given diameter of a smaller tolerance than the 0.020 inches commercially available for that size cable. Also, for example, a need is seen for a locking device configuration which is adaptable for different size cables, e.g., 1/4 inch, 1/8 inch (6 to 3 mm) and so on. Certain of the prior art could present problems with relatively small diameter cables due to dimensioning of the gripping members and tapered housing bores.
A need is also seen for devices comprising universally applicable gripping members configurations which can hold and lock a rod or cable regardless of the smoothness of the surface finish. Further, it is recognized by the present inventors that such a locking device should lock the cable or rod so that the cable or rod breaks prior to the device permitting the cable or rod to be removed therefrom in response to a load on the cable or rod. Also, it is desirable to provide anti-picking measures to preclude tampering.
A locking device according to one embodiment of the present invention comprises a housing having an opening on a first axis, a member for being received in the opening along the axis; and a serpentine shaped clip in radial resilient compressive engagement with one of the housing at the opening and member, the other of the housing and member having a tapered surface for receiving the clip, the clip, opening and tapered surface being dimensioned so that the received clip is wedged between the housing and member in response to relative axial displacement of the engaged clip to the tapered surface in the opening.
A locking device for securing a cylindrical member thereto according to a further embodiment comprises a housing having a bore which tapers from a larger diameter to a smaller diameter along a first axis, the housing having at least one opening for receiving the cylindrical member in the bore along the first axis; the clip being in the tapered bore, the clip comprising an elongated resilient member having a serpentine configuration which defines a bore having a second axis for receiving the cylindrical member, the clip being dimensioned to axially slidably receive the cylindrical member in compressive engagement therewith, the clip for axially displacing with the displacement of the cylindrical member and being dimensioned relative to the tapered bore and to the cylindrical member such that the clip is wedged in locked engagement to and between the cylindrical member and the housing in response to the displacement of the cylindrical member toward the smaller diameter.
According to a further embodiment, the clip is a homogeneous single piece material having at least one loop member extending from at least one further member, the further member extending in an annular direction about the second axis, the at least one loop member extending from at least one further member generally along the second axis.
In a still further embodiment, the clip comprises a single piece of homogeneous material including a plurality of loops extending generally along the second axis.
In a further embodiment, the loops are substantially symmetrical with respect to the second axis.
In a further embodiment, the clip comprises a first loop member having proximal and distal ends, the loop member extending along a second axis between the ends and a further member joined to the loop member at one loop member end and extending at least partially about the second axis to form a serpentine structure with the loop member, the serpentine structure being radially resilient relative to the second axis and dimensioned to extend at least partially about the received member in resilient radial compressive gripping engagement with at least one of the housing and received member, the tapered surface for receiving the clip and being dimensioned to permit the received clip to be displaced along the first axis.
In a further embodiment the clip is in radial resilient compressive engagement with one of the housing at a housing opening and member and extends along an axis a given length, the clip being in resilient radial engagement along substantially the axial length, the other of the housing and member having a tapered surface for receiving the clip, the clip, opening and tapered surface being dimensioned so that the received clip is wedged between the housing and member in response to relative axial displacement of the member to the housing.
In a still further embodiment, a clip is in radial resilient compressive engagement with one of the housing at a housing opening and member, the other of the housing and member having continuous dual mirror image tapered surfaces extending along an axis for axially receiving the clip, the clip, opening and tapered surfaces being dimensioned so that the received clip is wedged between the housing and member in response to relative axial displacement of the member to the tapered surfaces in either of two opposing directions in the opening.